Go opening theory
Encyclopedia
In the game of Go, the term opening theory refers to concepts which underlie where, why, in what order, and in what shapes
Shape (Go)
In the game of Go, shape describes the positional qualities of a group of stones. Descriptions of shapes in go revolve around how well a group creates or removes life and territory. Good shape can refer to the efficient use of stones in outlining territory, the strength of a group in a prospective...

 the first several moves are played. The middle game typically begins once the basic foundational areas called frameworks are established and "fighting" begins.

The opening is conceptually and traditionally divided for study into the sequences that are whole board openings and those that are corner openings. Each type constitutes a series of plays which have been studied for their balance (with the other) as well as for countermoves.

For a standard board, the most basic single concept for the opening is that plays in the corners are more efficient for making territory than plays on the sides or in the center.

Concepts

Opening theory is less dominant in terms of study, for those wanting to reach a good amateur level
Go ranks and ratings
Skill in the traditional board game Go is measured by a number of different national, regional and online ranking and rating systems. Traditionally, go rankings have been measured using a system of dan and kyu ranks...

, than in chess
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...

 or shogi
Shogi
, also known as Japanese chess, is a two-player board game in the same family as Western chess, chaturanga, and Chinese Xiangqi, and is the most popular of a family of chess variants native to Japan...

. It is, however, an important component of Go knowledge, though there is no single, codified source for it.

The standard sequences for the joseki
Joseki
In Go, are studied sequences of moves in the corner areas of the Go board, for which the result is considered balanced for both black and white sides. Because games typically start with plays in the corners, players often try to use their understanding of joseki to gain local advantages in the...

 in many cases come to a definite end, after which both players should move elsewhere. In some cases a sharp local struggle breaks out, which neither player should neglect. For those cases, the result of the opening may develop out of a 10×10 corner area into the rest of the board. Analysis without taking into account what other stones are in place then becomes somewhat meaningless. The longest 'book' corner openings are about 50-ply
Ply (game theory)
In two-player sequential games, a ply refers to one turn taken by one of the players. The word is used to clarify what is meant when one might otherwise say "turn"....

.

Most corner openings do not have special or picturesque names. A few that do are known by Japanese names: the taisha
Taisha joseki
The taisha joseki is the Japanese term for the most celebrated of all joseki in the game of go. It is often described in go literature as having a thousand variations ; this is more than a figure of speech, since many hundreds of subvariations have been documented, in high-level games, books and...

, the nadare (avalanche
Avalanche
An avalanche is a sudden rapid flow of snow down a slope, occurring when either natural triggers or human activity causes a critical escalating transition from the slow equilibrium evolution of the snow pack. Typically occurring in mountainous terrain, an avalanche can mix air and water with the...

), the Magic sword of Muramasa. These are among the most complex, and are contraindicated for novices.

Whole-board openings

Because each early move is typically isolated, and neither forced nor forcing, patterns for play on the whole board have seen much less systematic study than for joseki, which in contrast often involve contact plays which require specific and immediate responses. Hence a game of Go may easily explore an unfamiliar path.

Only a relatively small proportion of openings have a recognised name. These include the Three stars opening (sanrensei), Two stars opening (nirensei), "Pinwheel" or Shusaku opening and Chinese opening
Chinese opening (go)
The Chinese opening is an opening pattern in the game of Go...

 (Chinese fuseki). To be more precise, these are names for the moyo (framework) formations which Black makes on one side of the board. Since White has a choice of perhaps two dozen legitimate variations on the other side, these are in fact large complexes of openings.

The Chinese opening, which has an intricate history but was indeed developed by Chinese players, was very popular from about 1970 onwards, and has by go standards a thoroughly-researched theory.

Joseki

Joseki are "sequences" of moves which have been
  • played and documented in high-level play, and
  • studied and deemed as consisting of optimal (balanced) moves for both sides.


Joseki is a Japanese word (定石) (Korean
Korean language
Korean is the official language of the country Korea, in both South and North. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture in People's Republic of China. There are about 78 million Korean speakers worldwide. In the 15th century, a national writing...

 jungsuk), where jo (定) means "fixed" or "set", and seki (石) means stone(s). It thus literally means "set stones", as in "set pattern". Variations are shown to lead to different positional advantages and disadvantages for the two players in certain overall game situations. If Black and White both play the joseki correctly, they should achieve a balanced result within that particular corner; neither should have a large advantage, unless the opponent makes a mistake.

"Balance" typically refers to an equitable trade-off between securing territory in the corner versus making good thickness toward the sides and center. The assessment also takes into account who started and ended the corner sequence: if Black has played one more stone than White in the corner, for example, Black's result should be objectively better than White's, to reflect the extra investment of a play.

In application these concepts are in fact very dynamic, and often joseki are deviated from depending on the needs of the situation, and the opportunities available. While learning joseki is a tool to defend against a local loss, players can seek to take advantage by deviating from the joseki, or "pausing" it.

Usually joseki as a term (in literature in English) is applied to a set sequence happening in one corner in the opening stage. These sequences are not the only set sequences in the game, however. There are also joseki seen in the middle game: these include standard follow-ups to earlier joseki. Other examples are common techniques for invading or reducing frameworks. Learning to apply these so-called "middle game joseki" is one of the steps to becoming strong.

The current body made up of joseki is not fixed, but consists of patterns that have gained acceptance in professional games. That is, they form a consensus judgement that might change in the future, or with certain caveats.

Hence the basic definition may be misleading for new players in that joseki can be misconstrued as foolproof and unalterable, and are otherwise optimal for all situations. Some joseki are in fact useful only for study within an artificially confined corner, and in real play are only considered good form when used in proper combination with other plays on the board (ie. other joseki and fuseki moves).

Knowing a particular joseki simply means that one knows a sequence of moves, resulting in a balance or fair trade-off between their positions. This is in practice much easier than appraising how joseki relate to the rest of the board —hence knowledge of joseki is regarded as shallow, when compared with the ability to integrate a strategy into a complex game landscape.

There is a go proverb
Go proverb
Go proverbs are traditional proverbs relating to the game of Go, generally used to help one find good moves in various situations during a game. They are generalisations and thus a particular proverb will have specific situations where it is not applicable. Knowing when a proverb is inapplicable is...

 that states that "learning joseki loses two stones in strength," meaning that rote learning of sequences is not advantageous. Rather learning from joseki should be a player's goal.
Hence the study of joseki is regarded as a double-edged sword and useful only if learned not by rote but rather by understanding the principles behind each move.

Every joseki should be used as a specific tool that leaves the board in a particular shape. Just as using an improper tool in machinery can be devastating, choosing the wrong joseki can easily be worse than improvising one's own moves.

In his book A Way of Play for the 21st Century, Go Seigen
Go Seigen
Wu Qingyuan , generally known in the West by his Japanese name Go Seigen, is considered by many players to be the greatest player of the game of Go in the 20th century and of all time.-Biography:...

 compared choosing the proper joseki to choosing the proper medicine —pick the right one, and you feel better. Pick the wrong one and you die.(par.
Paraphrase
Paraphrase is restatement of a text or passages, using other words. The term "paraphrase" derives via the Latin "paraphrasis" from the Greek , meaning "additional manner of expression". The act of paraphrasing is also called "paraphrasis."...

)
Rui Naiwei
Rui Naiwei
Rui Naiwei is a Chinese professional Go player, now active in South Korea...

 similarly remarked that playing joseki is easy [but] choosing the right one [in a game] is hard.(par.)
A joseki may fall out of use for various reasons, some of which may often seem minor to the amateur player, and professionals may consider one variation suboptimal for a very specific reason.

There is no definitive guide to what is joseki; the situation with joseki dictionaries is similar to that of natural language dictionaries, in that some entries are obsolete and the listing is not likely to be complete. Studying joseki is only important part of developing one's strength
Go ranks and ratings
Skill in the traditional board game Go is measured by a number of different national, regional and online ranking and rating systems. Traditionally, go rankings have been measured using a system of dan and kyu ranks...

 as a player at some levels; the study of life and death
Life and death
Life and death is a fundamental concept in the game of Go, where the status of a distinct group of stones is determined as either being "alive", and may remain on the board indefinitely, or "dead," where the group will be lost as "captured"...

 and middle-game fighting are considered to be more important.

History

Go openings have been studied in depth for many centuries, and center
upon concepts of finding balance with the opponent. Because black moves first, opening moves for black are based on the concept of exploiting that first-move advantage (along with sente) to gain influence
Influence
Influence may refer to:In science and technology:*Sphere of influence , the region around a celestial body in which it is the primary gravitational influence on orbiting objects...

 (or strength) and thus establish areas of territory.
There is no complete theory of go, simply because the number of possible variations makes any literal study impossible. Hence even the opening is subject to changes of fashion, and also some notable periods of innovation.

Certain professional players are known for their use of specific or innovative types of openings, and their ability to combine their use of those openings with other strengths in competitive play.

The 10-10 point

Go Seigen
Go Seigen
Wu Qingyuan , generally known in the West by his Japanese name Go Seigen, is considered by many players to be the greatest player of the game of Go in the 20th century and of all time.-Biography:...

 played his third move (Black 5) on tengen
Tengen (Go)
Tengen is the name of a Go competition in Japan.The name Tengen refers to the center point on a Go board.The event is held annually, and has run continuously since its inauguration in 1975....

, in a 1933 game against Honinbo Shusai
Honinbo Shusai
is the professional name of Hoju Tamura, also known as , who was a Japanese professional Go player.- Biography :He was born in Shiba, Tokyo, son of Tamura Yasunaga, a retainer of the shogun. He learned go at age 10 and joined the Hoensha in 1883, then under the leadership of Murase Shuho. He was...

, the top player of the time. Go lost the controversial 4-month game, which was played over 14 sessions in a ryokan
Ryokan (inn)
A is a type of traditional Japanese inn that originated in the Edo period , when such inns served travelers along Japan's highways. They typically feature tatami-matted rooms, communal baths, and other public areas where visitors may wear yukata and talk with the owner.Ryokan are difficult to find...

in Tokyo from 16 October 1933 to 19 January 1934.

External links

  • Opening article at Sensei's library
    • This is the introductory opening article at the Go wiki "Sensei's Library".
      It branches out into several sub-articles and covers most of the basic opening patterns.
  • Sensei's Library, information about go dictionaries
  • Go Learn - openings
    • Series of articles on openings written by Charles Matthews 3-dan
      Go ranks and ratings
      Skill in the traditional board game Go is measured by a number of different national, regional and online ranking and rating systems. Traditionally, go rankings have been measured using a system of dan and kyu ranks...

      .
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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